Gov. Robert Ehrlich did the right thing last week when he endorsed a lawsuit by Maryland against the Environmental Protection Agency for weakening the Clean Air Act. He offered hope that he might become the moderate on pollution and preservation issues that he promised in his run for office.

In the federal court suit, Maryland joined a dozen other states in our part of the country challenging the Bush administrations brazen decision to scrap one of our basic pillars of clean air protection.

It hasnt been easy keeping up with all of this administrations rollbacks in regulations that protected our air, land and water. One reason is that this administration often chooses to gut obscure rules that people dont know much about. Thats what led to the suit by Maryland.

The regulation canned last week by the White House was called New Source Review, not something people normally discuss at the dinner table. What it did was require the oldest, dirtiest, coal-burning power plants and factories to install modern pollution control gear if they wanted to upgrade and expand operations.

Most of these plants are situated in the Midwest, and this worries planners in our region because air pollution moves eastward on prevailing winds. This turn of events should concern us along the Chesapeake Bay because of increasing evidence that airborne pollution is a growing threat to the Bays health. Roughly one-third of Bay-choking nitrogen comes from the air.

You cant talk about pollution without dealing with politics, and its worth noting that both political parties are predicting that the Midwest will determine the outcome of the next presidential election.

We cant know if politics had something to do with this administration giving this multi-billion-dollar gift to Midwestern industries at the start of the new political campaign. This president has little regard for anti-pollution rules in any season.

What we do know is that the present White House is fanatical about loyalty  which gets us back to Ehrlich.

You can bet that the Bush scorekeepers put a red check next to Ehrlichs name and that his endorsement of the lawsuit against the EPA will cost him down the line.

But we think that the loss of a highway grant or another such punishment is well worth the value of standing up for Maryland, the Chesapeake Bay and ourselves.

Ehrlich might want to recall the warning of Christine Todd Whitman, the moderate ex-GOP governor of New Jersey who left her job as EPA administrator in June after battling the White House over pollution control.

Whitman warned that there would be a terrible political price for killing the Clean Air Act, according to leaked documents. That wont be a cost that Ehrlich shares.